Formalin-fixed and paraffin-embedded nodal non-Hodgkin's lymphomas demonstrate the same chromosome changes as those found in frozen samples: a comparative study using interphase fluorescence in situ hybridization.

Cytogenetic studies in lymphomas classically require fresh or frozen tissue, whereas in many instances only paraffin-embedded biopsies are available. We applied an interphase FISH assay on nuclei extracted from thick paraffin sections to determine accuracy of molecular cytogenetics in such samples. Twenty-three lymphoma samples and 4 reactive lymph nodes were tested with various commercially available DNA probes, and hybridization patterns were compared with those obtained on frozen nuclei counterparts. Successful hybridization with all probes tested was observed for 23/27 (85%) paraffin-embedded tissues and for all (100%) frozen samples, and cut-off levels defining positivity were superimposable for both situations. Chromosome changes were detected in the same way, without any false-positive or false-negative cases. Hybridization signals observed on dewaxed samples were either those classically expected to define the relevant chromosome change or were atypical: all atypical changes could be demonstrated also into nuclei from the frozen counterpart. Moreover, all typical and atypical chromosome changes observed on frozen nuclei were also detected in paraffin-embedded tissues. Our study shows that our interphase FISH assay performed on paraffin-embedded samples is a valuable alternate to conventional methods to ascertain diagnosis of lymphomas as to include patients into therapeutic trials.     

Analysis of BCL2 and MYC expression in non-Hodgkin's lymphomas by in situ hybridization: correlation with chromosome translocations.

We have used an in situ hybridization method for analysis of expression of BCL2 and MYC on cytospun preparations of normal and malignant lymphoid cell lines and tissue sections of normal and malignant lymph nodes. The probes comprised 50-mer antisense oligonucleotides starting at the ATG codons of exon 3 of BCL2 and exon 2 of MYC. We studied the expression of these two genes in frozen tissue sections of biopsy specimens derived from normal and hyperplastic lymph nodes, B-cell lymphomas carrying the t(14;18)(q32;q21) and t(8;14)(q24;q32) translocations, and T-cell lymphomas with clonal chromosome abnormalities. While all proliferating cells expressed both genes, BCL2 expression was increased two- to threefold in follicular lymphomas with t(14;18) and MYC expression was increased two- to four-fold in high-grade lymphomas with t(8;14). These results are consistent with previous data on deregulated expression of these genes obtained from study of lymphoma cell lines carrying the relevant translocations.     

荧光原位杂交技术在淋巴瘤诊断中的价值

目的 探讨荧光原位杂交(FISH)检测在淋巴瘤诊断中的价值,为淋巴瘤的准确诊断提供依据.方法 以前瞻性非随机分组模式,采用三组IgH/bcl-2、IgH/CCNDl、API2/MALT1探针,对临床初诊为淋巴瘤的74例活检新鲜样本的瘤细胞进行FISH,检测其相应t(14;18)、t(11;14)及t(11;18)染色体易位,将检测结果与组织病理诊断进行比较评价.结果 74例中8例(10.8%)检测到染色体易位,分别为t(14;18)和t(11;14)各4例.62例组织病理诊断为淋巴瘤者中7例检测到染色体易位,分别为t(14;18)3例(组织病理诊断2例为滤泡性淋巴瘤、1例为结节硬化型霍奇金淋巴瘤);t(11;14)4例(组织病理诊断2例为套细胞淋巴瘤、1例滤泡性淋巴瘤,1例小淋巴细胞淋巴瘤).在组织病理未诊断为淋巴瘤的12例中,仅检测到1例t(14;18),而其组织形态显示为淋巴组织增生活跃,经FISH检测更正诊断为滤泡性淋巴瘤.25例弥漫性大B细胞淋巴瘤未检测到t(14;18).在其他有基因数目异常者56例(75.7%)中恶性病变52例(92.9%),与4例(7.1%)良性病变比较,病变性质与基因数目异常之间差异有统计学意义(P=0.011).结论 FISH技术检测淋巴瘤特异的遗传学异常对于复核组织病理诊断、鉴别其类型、亚型及病变的良、恶性有重要参考价值.     

滤泡型淋巴瘤中t(14;18)染色体易位的分析及其临床意义

目的探讨滤泡型淋巴瘤（FL）的分子遗传学特征及其在病理诊断中的意义。方法收集55例FL石蜡标本,对照组小B细胞淋巴瘤28例和反应性滤泡增生（RFH）10例,应用套式PCR技术检测FL中,免疫球蛋白重链基因（IgH）的克隆性重排;应用标准PCR技术检测55例FL中t（14;18）易位,以10例RFH做对照;采用双色荧光原位杂交（FISH）技术检测20例淋巴结FL中t（14;18）易位,以4例RFH作为对照;并与PCR检测结果进行比较。结果（1）55例FL中,结内49例,结外6例。男性33例,女性22例,男女比为1．5：1。发病年龄36—79岁（中位年龄57岁）;FL分级：FL1—3分别为25例、19例和11例。（2）55例中50例（90％）检出β-肌动蛋白（actin）,该50例中FR3A阳性24例（48％）,FR2阳性25例（50％）,其中15例（30％）呈FR3A和FR2双阳性,共34例（68％）IgH基因重排。对照组小B细胞淋巴瘤28例中,25例检出β—actin,其中FR3A阳性18例（64％）,FR2阳性17例（61％）,共24例（86％）可检测出克隆性IgH基因重排。4例RFH均未检出IgH基因重排。（3）在44例结内FL中检出15例（34％）t（14;18）易位,其中14例在MBR,1例在mcr。（4）20例中,有16例（80％）可检出t（14;18）易位。结论（1）IgH克隆性重排在FL中的检测率比其他小B淋巴细胞低。（2）FISH检测石蜡包埋组织中t（14;18）易位有助于FL的诊断。FISH比PCR的敏感性更好,操作简便,可用于检测石蜡包埋组织中的分子遗传学改变。     

眼附属器淋巴组织增生性病变的临床病理和分子遗传学特征及其意义

目的 分析眼附属器淋巴组织增生性病变的临床病理特点,探讨其分子遗传学特征及其意义.方法 收集1995-2007年37例眼附属器淋巴组织增生性病变石蜡组织标本(其中5例为反应性增生性病变,32例为淋巴瘤),依据2001年WHO肿瘤分类标准对32例淋巴瘤标本重新诊断分类.采用IgH、MALT1、bcl-6、c-Mye、bcl-2、CCND1、bcl-10、FOXP1双色分离重排探针、IgH/bcl-2双色融合易位探针和18号染色体着丝粒探针,利用间期荧光原位杂交(FISH)的方法 检测眼附属器淋巴组织增生性病变的分子遗传学特点.结果 32例淋巴瘤均为非霍奇金B细胞淋巴瘤.其中,黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(MALT)淋巴瘤28例(87.5%),滤泡性淋巴瘤2例,弥漫性大B细胞淋巴瘤2例.60.7%(17/28)的眼附属器MALT淋巴瘤携带分子遗传学异常.其中,IgH基因断裂1例,但未找到与其发生相互易位的伙伴基因;基因3拷贝者16例,其中MALT1基因、bcl-6基因和c-Myc基因3拷贝的发生率分别为25%(7/28)、43%(12/28)和7%(2/28).16例基因3拷贝病例中,两种基因3拷贝合并存在者5例,其中bcl-6基因合并MALT1基因3拷贝者4例,bcl-6基因合并c-Myc基因3拷贝者1例.进一步研究显示,MALT1基因3拷贝者均存在18号染色体三体.2例滤泡性淋巴瘤都携带t(14;18)(q32;q21)/IgH-bcl-2.2例弥漫性大B细胞淋巴瘤均存在遗传学异常,1例表现为bcl-6基因3拷贝合并18号染色体三体,另1例表现为bcl-6基因3拷贝合并IgH和c-Myc基因双断裂.5例反应性淋巴组织增牛性标本均未见分子遗传学异常.结论 MALT淋巴瘤是眼附属器最常见的淋巴瘤类型;间期FISH有助于淋巴组织增生性病变的良恶性鉴别及淋巴瘤的分类;MALTI基因3拷贝者由18号染色体三体所致;18号染色体三体和bcl-6基因3拷贝(可能为3号染色体三体所致)是眼附属器MALT淋巴瘤常见的分子遗传学异常.     

Genetic imbalances in primary gastric diffuse large B-cell lymphomas: comparison of comparative genomic hybridization, microsatellite, and cytogenetic analysis.

Extranodal malignant non-Hodgkin's lymphomas account for about 40% of lymphoid neoplasms, but few data are available concerning the genetic background of primary gastric diffuse large B-cell lymphoma (DLBCL). A study was performed of 27 primary gastric DLBCLs and 5 gastric DLBCLs with a concomitant low grade component of mucosa-associated lymphoid tissue-type lymphoma using comparative genomic hybridization (CGH), microsatellite studies, classic cytogenetics, and fluorescence in situ hybridization (FISH) to search for specific genetic aberrations. The most frequent aberrations were losses of material on chromosome 6q and gains of parts of chromosome 3. In three cases, a total of six high level DNA amplifications were detected, with five of them involving chromosomal regions not having been reported before in gastric DLBCL. A high overall concordance of 91.4% between microsatellite analysis and CGH was observed using DNA extracted from the same tissue block. The concordance achieved using DNA from different tissue blocks of the same patient was 85%. Microsatellite studies, CGH, FISH, and classic cytogenetics represent complementary techniques that facilitate a comprehensive view of genetic alterations in malignancies such as primary gastric DLBCL.     

Trisomy 3 in gastric lymphomas of extranodal marginal zone B-cell (mucosa-associated lymphoid tissue) origin demonstrated by FISH in intact paraffin tissue sections.

Some reports have indicated that trisomy 3 represents a characteristic chromosomal abnormality found in lymphomas arising in mucosa-associated lymphoid tissues (MALT)/extranodal marginal zone B-cells (MZBC). Traditional cytogenetic analysis of metaphase preparations is cumbersome and not always possible, especially in those situations in which the diagnosis in not suspected before a biopsy. Our aim is to use a relatively simple method to evaluate trisomy 3 in paraffin-embedded, formalin-fixed tissue, using fluorescence in situ hybridization (FISH) on intact tissue sections. Formalin-fixed, paraffin-embedded archival tissues from 30 cases (27 lymphoma and 3 chronic gastritis cases) were hybridized with a chromosome 3 specific alpha-satellite probe (ONCOR, Gaithersburg, MD). Three of four cases of gastric MZBC/MALT lymphoma revealed trisomy 3. Ten cases of lymphoma of possible or probable MZBC origin were examined, and four revealed trisomy 3. Five of 13 non-MZBC lymphomas revealed trisomy 3. None of the chronic gastritis cases nor normal tonsil cases revealed trisomy 3. Our results, using a different methodological approach, confirm the findings of others that trisomy 3 is an abnormality found in a significant proportion of lymphomas of MZBC origin. Our approach also makes possible interphase cytogenetic analysis (by FISH) of routinely processed formalin-fixed, paraffin-embedded tissues, without the need to disaggregate cells. It thus may facilitate genetic analysis on specimens previously deemed unsuitable for such analysis, particularly when tissue quantity is limited.     

Cytogenetic abnormalities detected by fluorescence in situ hybridization on paraffin-embedded chronic lymphocytic leukemia/small lymphocytic lymphoma lymphoid tissue biopsy specimens

Cytogenetic fluorescence in situ hybridization (FISH) panels are a major prognostic tool in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), but few data exist on using paraffin-embedded extramedullary tissue biopsy specimens for these purposes. Isolated whole nuclei were extracted from 20 paraffin-embedded tissue biopsy specimens with CLL/SLL and analyzed using a standard CLL FISH panel. FISH studies were successful in 18 (90%) of 20 cases, and chromosomal abnormalities were detected in 18 (100%) of the technically successful cases. Deletion 13q14.3 was most frequent (10 [56%]; isolated in 8 and with other abnormalities in 2), followed by trisomy 12 (5 [28%]), deletion 11q22.3 (4/16 [25%]), 14q32 (IGH@) translocation (3 [17%]), and deletion 17p13.1 (1/16 [6%]). One case with IGH@ translocation showed a BCL2 translocation partner. No cases showed 6q23 deletion. Results of this FISH panel performed on 42 additional peripheral blood (PB)/bone marrow (BM) CLL specimens were similar except for a significantly greater frequency of deletion 13q14.3 in combination with other aberrations. Cytogenetic FISH studies using paraffin-embedded tissue biopsy specimens in CLL/SLL had a high yield and, with 1 exception, demonstrated a profile similar to cases diagnosed in PB/BM.     

Comparison of fluorescence in situ hybridization analysis of isolated nuclei and routine histological sections from paraffin-embedded prostatic adenocarcinoma specimens.

Fluorescence in situ hybridization (FISH) is a powerful tool for quantitative analysis of chromosomes and genes and can be applied in a variety of specimens, including cell cultures, isolated nuclei from fresh and fixed tissues, and histological tissue sections. However, the results of FISH analysis of isolated nuclei in prostate cancer have not been previously compared with those from histological sections from the paraffin-embedded tissue blocks. To compare these methods, we studied isolated nuclei derived from 50-microns sections and adjacent 5-microns tissue sections from 10 cases of benign nodular hyperplasia of the prostate and 16 cases of prostatic carcinoma. FISH analysis employed centromere-specific probes for chromosomes 7, 8, 11, and 12. In benign tissue, the percentage of nuclei with three or more signals for chromosomes 7, 8, 11, and 12 was less than 3% for both isolated nuclei and tissue sections. However, the percentage of nuclei with no and one signals was less than 8% for isolated nuclei and more than 24% for tissue sections. In prostatic carcinoma, numeric chromosomal anomalies were found in 75% of cases by both FISH methods. However, isolated nuclei had more chromosomal tetrasomy than tissue sections (mean, 9.2 to 11.0% versus 5.1 to 5.6%, respectively). Conversely, intratumor heterogeneity of chromosomal anomalies was identified in 5 cases by FISH analysis of tissue sections but not in isolated nuclei. Cancer ploidy analysis by FISH correlated well with ploidy analysis by flow cytometry, although FISH was more sensitive for aneuploidy. We conclude that FISH analysis of isolated nuclei and histological tissue sections from paraffin blocks are reliable methods for detection of chromosomal anomalies in archival tissue of prostate cancer, although each method has advantages and disadvantages.     

Differentiation of follicular from mucosa-associated lymphoid tissue lymphoma by detection of t(14;18) on single-cell preparations and paraffin-embedded sections.

A 57-year-old woman was referred to the Kyoto Prefectural University of Medicine because of multiple polypoid lesions in the duodenum. On the basis of the histopathologic findings, mucosa-associated lymphoid tissue lymphoma had been diagnosed. The polypoid lesions did not show any improvement in spite of antimicrobial therapy for elimination of Helicobacter pylori. Because the disease remained stable during the clinical course, no other specific treatment was administered. We performed fluorescence in situ hybridization (FISH) analysis on a single-cell preparation obtained from the duodenal lesions, to assess the specific chromosome translocation. We identified BCL2/IGH fusion at a frequency of 83%. Two-color FISH was also performed on paraffin-embedded tissue sections, which demonstrated BCL2/IGH fusion-positive cells in neoplastic follicles. These findings, together with the CD10+ immunophenotyping of tumor cells, led to a diagnosis of primary follicular lymphoma of the duodenum. Interphase FISH with the IGH gene and oncogene probes is a rapid and powerful tool for assessing genomic changes in gastrointestinal lymphoma on single-cell preparations and tissue sections. This technique is particularly useful in view of the increasingly small core biopsy samples and needle aspirations obtained for diagnostic purposes.     

BCL10 in malignant lymphomas--an evaluation using fluorescence in situ hybridization.

BCL10 is a tumour suppressor gene originally cloned from a t(1;14)(p22;q32) breakpoint in a case of mucosa-associated lymphoid tissue (MALT) lymphoma. Translocations involving this gene, though uncommon, are sometimes encountered in MALT lymphomas. This gene is thought to play an important role in the development of malignant lymphomas. Fluorescence in situ hybridization (FISH) was therefore undertaken on 22 cases of malignant lymphoma of varying histology to establish the incidence of rearrangements involving the BCL10 gene. Initially, one case with a novel t(1;2)(p22;p12) translocation involving the BCL10 gene was identified, in a marginal zone lymphoma of the MALT type, and was reported elsewhere. Seven other cases were subsequently identified with abnormalities in the 1p region, including a translocation with a breakpoint in the 1p22 region in a case of lymphoblastic lymphoma. However, none of these involved the BCL10 gene. Mutation analysis of BCL10 was then performed on 57 cases of malignant lymphoma, including 17 MALT lymphomas, by single-strand conformational polymorphism (SSCP) analysis of tumour DNA. Tissue was obtained for mutation analysis for 12 of the 22 cases analysed by FISH. Selected cases with SSCP band shifts were further studied by direct sequencing. Polymorphisms were identified in eight cases, but no mutations of pathogenic significance were identified. Further RT-PCR and mutation analysis was performed on cDNAs from 12 cases (four MALT, seven diffuse large B-cell lymphoma, one Hodgkin's disease) in which DNA analysis had already been completed. This included the MALT lymphoma with the t(1;2)(p22;p12) rearrangement. Again, no mutations were identified in the coding sequence. This study confirms that rearrangements of the BCL10 gene are uncommon in lymphoma (1/22) and may be limited tothe MALT subtype of non-Hodgkin's lymphomas. It was also found that breakpoints or rearrangements in the 1p22 region do not necessarily involve the BCL10 gene. Moreover, the absence of mutations at both the DNA (0/60) and the mRNA (0/12) level indicates that this gene is not frequently inactivated by mutation, in those tumours in which it is not involved in translocations. Our findings suggest that the BCL10 gene is unlikely to have a frequent or key role in general lymphomagenesis.     

Interphase FISH detection of BCL2 rearrangement in follicular lymphoma using breakpoint-flanking probes

Rearrangement of the BCL2 gene is an important parameter for the differential diagnosis of non-Hodgkin lymphomas. Although a relatively large proportion of breakpoints is clustered, many are missed by standard PCR. A FISH assay is therefore desired. Up to now, a lack of probes flanking the BCL2 gene has limited the possibilities for a FISH assay to an approach based on colocalization of probes for BCL2 and the immunoglobulin heavy chain (IGH) locus. Intrinsically high rates of false positive nuclei and high interobserver variability make such assays unsuitable for use on lymphoma tissue samples, where tumor cells often form only a minority of the cell population. Using YAC end cloning techniques and screening of a PAC library, we have isolated PAC clones flanking the BCL2 gene. Using these PACs, and several cosmid clones in the second BCL2 intron, we developed a segregation-based interphase FISH assay with two probe combinations enabling separate detection of 5' and 3' (mbr/mcr) breakpoints. The assay was applied to a series of 40 follicular lymphomas. To evaluate the results, the same lymphomas were analyzed by DNA fiber FISH with a 600-kb set of BCL2 DNA clones labeled in alternating colors in combination with a color barcode covering the IGH locus. This approach allowed precise mapping of BCL2 breakpoints, and simultaneously showed juxtaposition of IGH genes to BCL2. Comparison of the results of interphase and fiber FISH showed complete correlation. Five cases were negative with both FISH techniques as well as with Southern blotting. Interestingly, all of these 5 cases lacked BCL2 overexpression as determined by immunohistochemistry, against 3 of 35 rearrangement-positive follicular lymphomas. Furthermore, absence of t(14;18) seemed to be correlated with a higher histologic grade (grades 2 and 3 according to Berard). These data indicate that the segregation-based interphase FISH assay detects 100% of BCL2 rearrangements. Because interpretation of the results is straightforward and requires no extensive experience, this assay may be the best available diagnostic test for BCL2 rearrangement. Genes Chromosomes Cancer 27:85-94, 2000.     

Immunoglobulin heavy chain rearrangements in primary brain lymphomas. A study using PCR to amplify CDR-III

Primary brain lymphomas (PBLs) have only rarely been analysed for immunoglobulin heavy chain (IgH) rearrangements. In this study, DNA was extracted from paraffin blocks in 23 cases of PBL and examined for IgH rearrangements using the polymerase chain reaction (PCR) to amplify the complementarity-determining region III (CDR-III) of rearranged IgH genes. Fifteen of the cases were phenotyped on paraffin-embedded tissue using a pan-B and pan-T antibody (L26 and UCHL-1, respectively). The remaining eight cases were not phenotyped for lack of tissue. For comparison, we used DNA extracted from paraffin blocks of normal brain, lymph nodes with lymphoid hyperplasia, and non-lymphoid malignancies. PCR products were examined by polyacrylamide gel electrophoresis. Among the ten B-cell PBL; four had a pattern indicative of IgH rearrangement, one had a germline pattern, and five had no detectable PCR products. Among the five T-cell PBLs, one had a germline pattern and four had no detectable products. Among the eight untyped PBLs, two had IgH rearrangement, four had a germline pattern, and two gave no detectable products. DNA from non-lymphoid tissues gave a consistent germline pattern, while DNA from polyclonal lymphoid populations (lymph node) had a pattern of polyclonal IgH rearrangement. In a dilution study, a clonal rearrangement could be detected as long as the clone's DNA constituted at least 10 per cent of the total DNA. PCR to amplify CDR-III can be successfully applied to DNA extracted from paraffin blocks, and it detected a clonal rearrangement in 50 per cent of cases that gave a detectable pattern. This allows clonality analysis of tissue unsuitable for conventional Southern blot analysis. Furthermore, B-cell PBLs have IgH rearrangements similar to those of extracranial B-cell neoplasms.     

Detection of t(14;18) in follicular lymphoma by dual-color fluorescence in situ hybridization on paraffin-embedded tissue sections

We studied the incidence of t(14;18)(q32;q21) in 54 patients with follicular lymphoma (FL) by dual-color fluorescence in situ hybridization on paraffin-embedded tissue sections (tissue-FISH) using probes for BCL2 and immunoglobulin heavy chain (IGH) genes. The t(14;18) was detected in 28 (56%) of 50 patients, who were successfully analyzed. On the other hand, BCL2 protein expression was detected in 45 (83%) of 54 patients evaluated by immunohistochemical staining. There was a discrepancy between t(14;18) and BCL2 expression. The absence of t(14;18) was associated with disease-free survival (P=0.02). There was no statistical difference, however, in overall survival and failure-free survival between the t(14;18)-positive and -negative groups. Tissue-FISH should be of great value to detect t(14;18) in FL because this method enabled us to demonstrate specifically t(14;18)-positive individual cells in neoplastic follicles on paraffin-embedded tissue sections. Furthermore, tissue-FISH can be applied to small specimens obtained from endoscopic biopsy or specimens obtained more than 10 years ago. We validated the usefulness of tissue-FISH as a diagnostic procedure and retrospective meta-analysis for malignant lymphoma.     

Contribution of IgH-PCR to the evaluation of B-cell lymphoma involvement in paraffin-embedded bone marrow biopsy specimens

We investigated whether the determination of clonality by polymerase chain reaction (PCR) analysis of immunoglobulin heavy chain (IgH) gene rearrangements could be helpful in the evaluation of B-cell lymphoma (BCL) involvement of bone marrow (BM) biopsy specimens. We evaluated 83 paraffin-embedded BM biopsy specimens from 26 patients with BCL. When BM biopsy specimens considered positive, "suspicious," or negative by morphologic and immunohistochemical examination were evaluated by PCR, a monoclonal B-cell population was detected in 81% (39/48), 64% (9/14), and 11% (2/18), respectively. In most cases, a reproducible monoclonal IgH gene rearrangement was observed from BM and extramedullary sites. Nevertheless, in 4 cases, a different and independent monoclonal IgH rearrangement was observed during the disease course. PCR is efficient and complementary to morphologic and immunohistochemical examination for the evaluation of BCL involvement of BM biopsy specimens, especially when a reproducible rearrangement is found in 2 different samples.     

BCL10 expression in normal and neoplastic lymphoid tissue. Nuclear localization in MALT lymphoma

BCL10 is an apoptotic regulatory molecule identified through its direct involvement in t(1;14)(p22;q32) of mucosa-associated lymphoid tissue (MALT) lymphoma. We examined BCL10 protein expression in various normal tissues and B-cell lymphomas by immunohistochemistry of formalin-fixed and paraffin-embedded tissues using mouse BCL10 monoclonal antibodies. BCL10 protein was expressed in lymphoid tissue but not in 21 various other tissues with the exception of breast. In normal B-cell follicles, the protein was expressed abundantly in the germinal center B cells, moderately in the marginal zone, but only weakly in the mantle zone B cells. Irrespective of their stage of B-cell maturation, BCL10 was predominantly expressed in the cytoplasm. In contrast, each of the four MALT lymphomas with t(1;14)(p22;q32) showed strong BCL10 expression in both the nucleus and cytoplasm. Twenty of 36 (55%) MALT lymphomas lacking the translocation exhibited BCL10 expression in both the nucleus and cytoplasm although at a much lower level, whereas the remaining 16 cases displayed only cytoplasmic BCL10. Unlike MALT lymphoma, both follicular and mantle cell lymphomas generally displayed BCL10 expression compatible to their normal cell counterparts. Our results show differential expression of BCL10 protein among various B-cell populations of the B-cell follicle, indicating its importance in B-cell maturation. The subcellular localization of BCL10 was frequently altered in MALT lymphoma in comparison with its normal cell counterparts, suggesting that ectopic BCL10 expression may be important in the development of this type of tumor.     

Tissue microarray-based screening for chromosomal breakpoints affecting the T-cell receptor gene loci in mature T-cell lymphomas

The pathogenesis of mature T-cell non-Hodgkin lymphomas (T-NHLs) is poorly understood. Analogous to B-cell lymphomas, in which the immunoglobulin (IgH) receptor loci are frequently targeted by chromosomal translocations, the T-cell receptor (TCR) gene loci are affected by translocations in a subset of precursor T-cell malignancies. In a large-scale analysis of 245 paraffin-embedded mature T-NHLs, arranged in a tissue microarray format and using improved FISH assays for the detection of breakpoints in the TCRalpha/delta, TCRbeta, and TCRgamma loci, we provide evidence that mature T-NHLs other than T-cell prolymphocytic leukaemia (T-PLL) also occasionally show a chromosomal rearrangement that involves the TCRalpha/delta locus. In particular, one peripheral T-cell lymphoma (not otherwise specified, NOS) with the morphological variant of Lennert lymphoma displayed a chromosomal translocation t(14;19) involving the TCRalpha/delta and the BCL3 loci. A second case, an angio-immunoblastic T-cell lymphoma (AILT), carried an inv(14)(q11q32) affecting the TCRalpha/delta and IgH loci. FISH signal constellations as well as concomitant comparative genomic hybridization (CGH) data were also suggestive of the occurrence of an isochromosome 7, previously described to be pathognomonic for hepatosplenic T-cell lymphomas, in rare cases of enteropathy-type T-cell lymphoma.     

中国南方地区原发性眼附属器黏膜相关淋巴组织结外边缘区B细胞淋巴瘤分子遗传学异常

目的 探讨中国南方地区原发性眼附属器黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(简称MALT淋巴瘤)分子遗传学异常的发生情况.方法应用间期荧光原位杂交(FISH)方法,检测57例来自中国南方部分地区眼附属器MALT淋巴瘤病例组织中t(11;18)(q21;q21)/API2-MALT1、t(1;14)(p22;q32)/IgH-bcl-10、t(14;18)(q32;q21)/IgH-MALT1以及涉及bcl-6和FOXP1基因的染色体易位等分子遗传学异常.结果 57例眼附属器MALT淋巴瘤标本中,有9例携带染色体易位,总的发生率为15.8%.其中4例(7.0%)为t(11;18)(q21;q21)/API2-MALT1,1例(1.8%)为t(14;18)(q32;q21)/IgH-MALT1,1例(1.8%)为涉及bcl-6基因的染色体易位,3例(5.3%)为涉及IgH但未知与其易位伙伴基因的染色体易位.另外,伴有3个bcl-6基因或3个MALT1基因拷贝的分别有17例(29.8%)和21例(36.8%),同时伴有3个bcl-6基因和3个MALT1基因拷贝的有12例(21.1%).结论中国南方地区眼附属器MALT淋巴瘤中,存在MALT淋巴瘤特异性相关染色体易位t(11;18)(q21;q21)/API2-MALT1和t(14;18)(q32;q21)/IgH-MALT1,与中国北方地区和北美的报道有明显差异,进一步证实眼附属器MALT淋巴瘤的染色体易位存在地域性差异.MALT1基因3拷贝和bcl-6基因3拷贝现象是中国南方地区眼附属器MALT淋巴瘤中最常见的分子遗传学异常,提示其可能与MALT淋巴瘤的发病机制有关.     

Trisomy 12 in pediatric granulosa-stromal cell tumors. Demonstration by a modified method of fluorescence in situ hybridization on paraffin-embedded material.

The use of fluorescence in situ hybridization (FISH) to detect chromosomal abnormalities has many applications. Use of FISH on archival, paraffin-embedded material has been limited to microscopic sections. We have carried out FISH on preparations of disaggregated nuclei obtained from paraffin-embedded tissue to evaluate chromosome 12 copy number in granulosa-stromal cell neoplasms occurring in infants, children, and adolescents. Trisomy 12 was detected in the majority of cells from three of four juvenile granulosa cell tumors (three ovarian and one testicular) and one malignant granulosa cell tumor. Tetrasomy 12 was observed in a case of ovarian thecoma.     

用间期核双标记荧光原位杂交技术检测BCL2原癌基因易位

目的 建立一个准确易行的诊断非何杰金氏淋巴瘤的实验室指标。方法 建立了以BCL2酵母人工染色体克隆yA153A6、以及免疫球蛋白重链基因（IgH)噬菌体克隆H24为探针的双标记荧光原位杂交技术,用以在间期核中检测BCL2原癌基因易位,结果 在滤泡性淋巴瘤细胞系SU-DHL-6细胞中,BCL2和IgH的杂交信号呈非随机分布,与一个BCL2等位基因易位到14号染色体IgH基因之上相对应,一个BCL2和一个IgH杂交信号始终紧密相连,而在正常淋巴细胞中,这两种基因的杂交信号至少保持1/10核直径的距离。结论 该方法客观明了,准确易行,不受标本中分裂相数量和质量的限制。可望成为临床诊断非何杰金氏淋巴瘤的常规手段。